Estudos moleculares e ambientais sobre o sistema de determinação sexual de tambaqui Colossoma macropomum (Cuvier, 1818)

Abstract

The aquaculture industry in Brazil still presents several technological challenges to be overcomed to achieve high productivity in order to supply the growing demand for animal protein. However, currently its biggest bottleneck is to adapt to the concepts of sustainability, and this implies developing innovative processes and products applied to increase productivity in this sector at the same time that preserves the natural environment and human health. Sexual development is a complex, multi-step process that involves the determination, differentiation and maintenance of sex, culminating in the production of fertile sperm or eggs for germline transmission. In this sense, the most promising techniques in aquaculture depend on the previous knowledge of all these mechanisms. Tambaqui is the most produced native species in fish farming in Brazil, in 2021 represented 16,9% of the total production of farmed fish. It presents sex dimorphic growth;, indicating the great potential for the use of monosex populations in this species. In this context, the present thesis was divided into two chapters. The first chapter brings the results of environmental manipulation and gene expression analysis to examine the effect of different temperatures on the sex ratio and transcriptional profile of genes involved in sex determination in tambaqui. This manuscript is published by Aquaculture International. In the second chapter, aiming at identifyinfg the sex master gene(s) of tambaqui, the whole genome sequence (WGS) readings of male and female gDNA pools were obtained, and 11,200 SNPs were mapped, and two sex-specific male tambaqui genomic regions were identified. We were not able to identify a candidate gene with this approach; however, we present regions that are very promising to host the sex region of tambaqui.